Editing Defense Switched Network

{{Short description|Communication Service for the United States Department of Defense}}
The '''Defense Switched Network''' ('''DSN''') is a primary information transfer [[telecommunications network|network]] for the [[Defense Information Systems Network]] (DISN) of the [[United States Department of Defense]].  The DSN provides the worldwide non-secure voice, [[secure voice]], data, [[Fax|facsimile]], and [[video teleconference|video teleconferencing]] services for [[United States Department of Defense|DOD]] [[Command and Control (Military)|Command and Control]] (C2) elements, their supporting activities engaged in [[logistics]], [[personnel]], [[engineering]], and [[intelligence (information gathering)|intelligence]], as well as other [[Federal government of the United States|federal]] agencies.

In 1982, the DSN was designated by the [[Office of the Secretary of Defense]] (OSD) and the [[Joint Chiefs of Staff]] (JCS) as the provider of long-distance communications service for the DOD.  The DSN is designated as a primary system of communication during peacetime, periods of crisis, preattack, non-nuclear, and post-attack phases of war.  The network assures nonblocking service for users with "flash" and "flash override" [[autovon|precedence capabilities]]. Key users include the [[National Command Authority (United States)|National Command Authorities]], [[Combatant Command|Commanders of the Combatant Commands]], and subordinate component commanders. DSN replaced the older [[Autovon]] system.

The DSN consists of four subsystems:
*Switching,
*Transmission,
*Timing and Synchronization, and
*[[Network administrator|Network Administration]] and Management.
The DSN Switching Subsystem consists of multifunction, [[Class 4 telephone switch|stand-alone tandem]], [[Class 5 telephone switch|end office]], and remote switching units.  Using the transmission, timing, and control elements of the DISN, they interconnect all military locations worldwide and provide end-to-end long-distance common user and dedicated voice, secure voice, data, and video services worldwide.

In addition to nonsecure voice, data, and video services, the DSN will provide transmission, switching, and support services for Secure Telephone Units, Third Generation ([[STU-III]]s, now obsolete), the [[Secure Terminal Equipment]] (STE), the [[Defense Red Switch Network]] (DRSN), the dial-up alternative routing for the Unclassified  but Sensitive [[Internet Protocol]] (IP) Router Network ([[NIPRNet]]), and the Secret IP Router Network ([[SIPRNet]]). The DSN can also provide access to the [[Government Emergency Telephone System]] (GETS).

==Area codes==
Eight [[area codes]] are used to cover certain geographical areas for regular voice communications:<ref>{{cite web|url=http://www.disa.mil/network-services/voice/sbu-voice/using-dsn/dsn-tutorial/area-codes|title=Sensitive but Unclassified Voice Training|website=DSN - Using the DSN|accessdate=28 December 2016}}</ref>
*311 for [[AFRICOM]]
*312 for the [[Continental United States]] ([[NORTHCOM]]) and [[Puerto Rico]]
*313 for the [[Caribbean]]
*314 for [[EUCOM]]
*315 for [[United States Pacific Command|INDOPACOM]]
*317 for [[Alaska]]
*318 for [[CENTCOM]]
*319 for [[Canada]] (Canadian Switched Network (CSN))

Other area codes are assigned to functional areas:
*20x for interface with the [[United Kingdom]]'s Defence Fixed Telecommunications Service (DFTS)
*606 for interface with [[NATO]]'s Core Network (NCN)
*7xx for interface with [[Australia]]'s Defence Voice Network (DVN)
*715 for interface with [[New Zealand]]'s Defence Telephone Network (DTelN)

==References==
{{Reflist}}

==External links==
* [https://www.disa.mil Defense Information Systems Agency] (DISA)
* [https://www.disa.mil/NewsandEvents/Media-Resources DISA Media Resources Page]
* [https://web.archive.org/web/20160417090807/http://www.disa.mil/Network-Services/Voice/SBU-Voice/History A brief history of the DSN] US Government Defense Information Systems Agency
* [http://www.disa.mil/_large_files/dsn_movie.mpg DSN Movie] US Government Defense Information Systems Agency
* [http://www.disa.mil/Services/Network-Services/Voice/SBU-Voice/DSN-Movie-Transcript DSN Movie Transcript] US Government Defense Information Systems Agency

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[[Category:United States Department of Defense agencies]]
[[Category:Military communications of the United States]]

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